Strecth poster to fit Aeon Nox Silvo?

I have all my media at an FTP and i have every movie in separate folder with nfo, fanart an poster.

Example:
Folder: 101 Dalamtiner
Files in folder:
101 Dalamtiner.avi
101 Dalamtiner.nfo
101 Dalamtiner-fanart.jpg
poster.jpg

I dont get all posters to show, i guess they have the wrong aspect example 350 x 491.

I have changed all

Code:
scale</aspectratio>

to

Code:
stretch</aspectratio>

as i read in another thread. First i just changed it in View_57_Shift.xml file (i use Shift Small) but nothin happend so i changed all the xml files in the skin.aeon.nox.silvo folder but nothing happens,

Am i doing something wrong? I have tried to remove the textures13.db, clean the library och delete and add the source again.